The present invention refers to glass modules for the construction of equipment— and installations and pipe works, their use, as well as equipment, installations and pipe works assembled from these modules.
It is known to construct equipment, installations and pipe works, for example for the chemical industry, the pharmaceutical industry or the food industry from glass building modules. The glass building modules are assembled for each of the different purposes from suitable glass, in particular, from boron silicate glass. One of the foremost requirements of the glass building modules, respectively the equipment, installations and pipe works assembled therefrom, is the necessary chemical stability against the substances produced therefrom or that are transported at the intended work temperatures, as well as the necessary mechanical properties, in addition to which, the required stability at resulting temperatures and pressures and the integrity of the glass surface in the intended environment must be taken into consideration. In order to ensure protection of the glass surface of the glass building modules, for example those made from boron silicate glass against exterior damage, for example scratches or blows, it is customary in the equipment and installation construction field to protect the glass surface by means of coverings or coatings. A common protective cover is a transparent layer of a polyurethane basis, which is commercially known as Sectrans. Such Sectrans coverings are applied to the glass surface by spraying them onto the glass surface in defined layers. Permanent use temperature is 140° C., but short-term temperatures up to 180° C. are permissible. With a Sectrans coating not only is the glass surface protected against scratches and blows, but protection against splintering when indeed a glass break occurs, is also ensured. In an operation carried out without pressure, the Sectrans coating can also provide a certain protection against the leakage of a medium from broken glass equipment.
Another possibility to protect surfaces of glass modules and installations is provided when coating the glass modules with glass fiber mats, which are placed onto the glass module and which are subsequently soaked in polyester resin (“GFP-coating”). Such coatings are, in general, sufficiently transparent although they do not achieve the transparency of the above Sectrans coatings. The maximum operating temperature of GFP coated glass modules is 150° C.
The afore-described coverings and coatings, while improving the mechanical properties, are from materials that are electrically non-conductive having an electric surface resistance of typically above 1012 Ω, as compared to uncoated glass they are however, electrostatically more chargeable. Uncoated glass normally forms at its surface a watery film and thereby normally has a significantly reduced electrical surface resistance, so that according to the guidelines “Statistical Electricity” No. ZH 1/200 of the BG-Chemie, normally no special protective measures against electrostatic charges are required. With glass surfaces which are in contact with the atmosphere, the specific electrical surface resistance remains at normal air humidity with maximal 106 Ω in an uncritical range.
Local or extended electrostatic charges of non-conductive, i.e. modules and pipe works and installations constructed therefrom and not coated with conductive layers, can effect spark or brushing discharges during certain chemical processes leading to ignition of the material mixture. The afore-described glass modules and installations with coatings or polyurethane layers must therefore be secured against improper electrostatic charges when utilizing ignitable material mixtures.
Likewise, installations made from untreated glass, under certain circumstances can become potentially dangerous to charging, namely when the glass surfaces are not in contact with moist ambient air, but with non-aqueous and/or water binding media, such as for example benzol or toluol, in that they lack the protective and conductive watery film.